Question

10. (14 pts) In the past, the mean lifetime of diesel engine fuel injectors has been 10,500 operating hours, with a standard deviation of 1300 hours. A new injector is available that is promoted as lasting longer than the old version. In a test of 50 of the new injectors, the mean operating life was found to be 10,800 hours. Using these data, perform a z-test of Ho: mu<=10,500 hours versus H1:mu>10,500 hours. Then use the appropriate statistical table to determine the approximate p-value for the test.

Answer 1

| 1 : A = 1 0 5 0 0 . Hiiu y 10500 n = 50, F = 10800, 0-1300, The test statistic z= * -u 1 10800 10500 Z = - 1. 13001150 =163). The p-value = {1- P(Z = 1.63]] reight tailed test = 1-0.9484 = 0.05155 -0.0516 Po value = 10.0516 Bras),